THE EFFECTS OF CHECK-SPRING TRAVEL ON LOCKSTITCH SEWING Available to Purchase

The stitch formation process of a lockstitch sewing machine has been investigated with the aid of transducers which facilitate real-time monitoring of the sewing cycle. It has been found that increasing the travel of the check-spring by three millimetres from the normal position significantly reduces needle thread consumption per stitch and increases the peak dynamic needle thread tension. This change in lockstitch formation has a profound effect on the geometry of the stitch and the theoretical performance of the stitch under longitudinal load. The ability to reduce static thread tension settings after extending the check-spring travel can be employed as a remedy for tension induced seam pucker.